Improvement in spokes for vehicle-wheels



C. W. LATHAM.

Spokes for Vehicle-Wheels.

NOM. `Patented Mag/19.1874.

WM@ few/C gym UNITED STATES PATENT FFIGE.

CHARLES W. LATHAM, OF MYSTIC RIVER, CONNECTICUT.

IMPROVEMENT IN SPOKES FOR VEHICLEWHEELS.

Specification forming part of Letters Patent No. 151,141, dated May 19, 1874; application filed February 4, 1874.

,To all whom it may concern:

Be it known that I, CHARLES LATHAM, ot' Mystic River, in N ew London county and State of Connecticut, have invented certain Improvements in Wheels for Vehicles, of which the following is a specification:

My invention relates to that class of wheels which have wooden spokes driven into a wooden hub; and it consists in an improved form of the tenons of the spokes, whereby greater strength and durability is g'iven to the wheel.

In the accompanying drawing, Figure l is a side view of a spoke, showing the forni of my improved tenon, and Fig. 2 is a sectional view through the center of the spoke and hub, showing the tenon driven into the inortise, and the manner in which the bers of the wood in the tenons are condensed in the inortise.

A represents one of the spokes, and B the hub, of a wheel. C is the tenon of the spoke, and D is the inortise into which the tenon C is driven. As now ordinarily made and used one of the two narrow sides or edges of the tenon oi' the spokes is made straight in the line ot' the body of the spoke, and the other is slightly' beveled or tapered, and the ends of the mortises are also made tapering or converging, so as to conform to the tenons. With this ordinary shape of the tenon there is, in driving the spoke sutticiently tight for service, a great'tendency to crush in and break off more or less of the bers of the wood upon the inclined edge of the tenon by the sharp outer edge of the end of the mortise. This always produces a weak place upon that edge of the tenon, which is constantly aggravated by the strains to which the wheel is subjected in use, until the tenon breaks off, when it will be found by examination that the fracture in almost every instance began at said described weak point upon the inclined edge of the tenon, next to the shoulder of the spokes.

My improvement consists in making what is ordinarily the tapered or beveled edge o the tenon into the form of a circular arc, as shown at c c in Fig. l. This curve or fullness upon the edge of the tenon, while the spoke is being driven in, sets back the wood at that end of the mortise somewhat, thus protecting in a great measure the edge of the tenon next the shoulder from being crushed in and injured. It also makes more fullness upon that edge of vthe tenon next the shoulder after it is driven into the hub, as shown in thc drawing, thus preventing the bers ot' the wood from being bent sharp inward at the shoulder', as they ordinarily are by the outer edgeof the mortise. It also equalizes the pressure and strain upon the tenon, for

the point of greatest pressure is some distance within the mortise, so that the tenon is held with a more even and equal pressure against the opposite end of the inortise; hence, for these reasons, the spokes are not so liable to break oft' at the shoulders ot' the tenons, as hereinbefore described.

I claim as iny invention- A wooden spoke for carriage-wheels, which has the inclined or tapered edge of the tenon made in the form of the circular arc c c, subA stantially as and for the purpose set forth.

CHAS. W. LATHAM.

Witnesses:

p WEBSTER PARK,

A. F. PARK. 

